1. Field of the Invention
The present invention relates to a construction machine such as a hydraulic excavator, more particularly to a construction machine including a remote control valve provided beside an operator's seat, a hydraulic valve configured to be operated by the remote control valve, and a pilot hose interconnecting the remote control valve and the hydraulic valve.
2. Description of the Background Art
The background art of the present invention will be described by taking a small-size hydraulic excavator shown in FIG. 6, as an example.
This hydraulic excavator comprises a crawler-type lower travelling body 1, an upper slewing body 2 mounted on the lower traveling body 1 in such a manner as to be slewable about an axis X perpendicular to a ground surface, and a work attachment AT attached to a front portion of the upper slewing body 2. The work attachment AT includes a boom 3, an arm 4, a bucket 5, and respective hydraulic actuators for actuating the boom 3, the arm 4 and the bucket 5, namely, a boom cylinder 6, an arm cylinder 7 and a bucket cylinder 8.
The upper slewing body 2 includes an upper frame 9, on which a seat stand 10, an operator's seat 11 provided on the seat stand 10, a canopy 12 covering the operator's seat 11 from above, various manipulation devices, an engine, and engine-related devices are mounted. Other than this canopy type, there is also a type in which a cabin is provided in place of the canopy 12, and the seat stand 10 and the operator's seat 11 are provided inside the cabin, namely, a cabin type.
As shown in FIG. 7, the upper frame 9 includes a bottom plate 13, and a floor plate 14 disposed above the bottom plate 13 with a vertical interval. There is formed an underfloor space S in an underfloor region of a front and left portion of the upper frame 9, that is, between the bottom plate 13 and the floor plate 14. In the underfloor space S is installed a multiple control valve unit 15. The control valve unit 15 is an assembly of a plurality of hydraulic-pilot-controlled control valves (see JP 2008-31817 A and JP 2002-227249 A). The terms “front (forward)”, “rear (rearward)”, “right (rightward)” and “left (leftward)” mean directions on the basis of an operator seated in the operator's seat 11.
The control valve unit 15 is attached, for example, onto the bottom plate 13. On the other hand, there are provided a plurality of remote control valves 16 above the seat stand 10. The plurality of control valves included in the control valve unit 15 are operated by respective manipulations applied to the remote control valves 16.
Rearward of the underfloor space S stands upright a partition wall 17. The partition wall 17 defines an engine room 18 beneath the operator's seat 11 and the seat stand 10 supporting the operator's seat 11.
The plurality of remote control valves 16 are distributed on right and left sides of the operator's seat 11 in a front end region of an upper surface of the seat stand 10, and the remote control valves 16 and the control valves of the control valve unit 15 are interconnected through a plurality of pilot hoses H.
As regards routing of the pilot hoses H, particularly, routing of the pilot hoses H which interconnect the remote control valves 16 located on a side opposite to an entrance way for the operator's seat 11 (in the example shown in FIG. 7, the right remote control valve 16: this remote control valve 16 will hereinafter be referred to as “inward remote control valve”) and the control valve unit 15 installed in the underfloor space S as mentioned above, there is the following problem. The position of the inward remote control valve 16 is set to the position for the easiest manipulation by a seated operator, with respect to a height direction, a front-rear direction and a right-left directions, and the space between a hose connection port in a lower surface of the inward remote control valve 16 located at the set position and the upper surface of the seat stand 10 is defined as a routing space: this routing space can have only a small height dimension as shown in FIG. 7, which requires the pilot hoses H to be bent with a great curvature within the routing space when they are routed. The routing with such large-curvature bending requires a complicated joint structure, thus involving increased component cost and deteriorated production efficiency due to an increase in workload in an assembling line.